Compressor



Jan. 25, 1938. I b. R. BURKE 2,106,236

.' COMPRESSOR Filed Aug. 30, 1935 6 Shets-Sheet 1 WWW '1 Mull; W J23 I j I INTENT/11L lHBUHKE' 4 .JT'TUJE'NETEL.

B. R. BURKE Jan; 25, 1938.

COMPRESSOR Filed Aug. 30, 1953 6 Sheets-Sheet 2 QTTUENEYE 6 Sheets-Sheet 3 'JNVENTQZL EREJUQKE' 1 I]? .Z1TT-U1; NEY5 B. R. BURKE COMPRESSOR Filed Aug. so, 1955 Jan; 25, 1938.

Jan. 25, 1938. B. R. BURKE 2,106,236

COMPRESSOR Filed Aug. :50, 1933 6 Sheets-Sheet 4 lW/ENTUJL M in U 1" T UHNEYEL Jane 25, 19330 I a R BURKE I 2,106,236

JNVENTUA M gar T GENE 215i Jan. 25, 1938.

B. R. BURKE COMPRES SOR Filed Aug. 50, 12533 6 Sheets-Sheet 6 wnwhk INTENT/12L j QBJZE UEKE' W W Patented Jan. 2, N3

ST E

This invention relates to improvements in compressors and particularly to compressors which have been designed for use in mechanical re- .frigeration although the invention may be em-.

pioyed wherever it is desired to compress a gas.

An object of the invention is to provide a multiple cylinder compressor of compact form and which is so designed as to reduce vibration and objectionable noises to a minimum. In this respect an object of the invention is to provide a compressor wherein there are but a very few reciprocating parts, thus reducing the vibration.

Another object of the invention is to provide a compressor having a quiet valve action. A quiet valve action in a compressor used in mechanical refrigeration is highly important in that a large percentage of objectionable noises which are generated in the compressor result from the valves.

Another object of the invention is to provide a refrigerating system wherein acompressor is used and wherein the lubricating oil used to lubricate the compressor is continually separated from thecompressed gas and returned to the oil :5 supply that lubricates the compressor. In many types of mechanical refrigeration wherein a com- -pressor is used the gas that is compressed picks up the oil in the cylinder or cylinders of the compressor. It shortly becomes saturated with the oil and the oil is carried by the gas through "the system, collecting at various points such as, for example, in the cooling coil. This results in the compressor having-all of the lubricating oil removed and carried away from the crank case 3 5 with the result that bearings run dry and either The ultimate result burn or become very loose. is that the compressor either becomes badly damaged or becomes very noisy and it is necessary to either repair or replace parts or to tighten up bearings to eliminate the objectionable noise.

- fi() oil is continually being removed from the gas and returned to the compressor so that an adequate supply of lubricant will always be maintained in the compressor.

Another object of the invention is to provide 55 an improved compressor of simple and sturdy construction which can be easily assembled and which can be easily disassembled for purposes of repair or replacement should occasion require.

Another object of the invention is to provide an improved compressor of novel design which eliminates the use of the conventional crank shaft, connecting rods, bearings therefor, wrist pins, eccentric straps, and the like; which parts tend to produce vibration in the compressor,

which is. objectionable. Not only does the improved compressor avoid the use of such parts which tend to produce vibration but the new design is such as to reduce friction and also wear on the various bearing surfaces. In the compressor of the improved design the arrangement of parts is such that should certain parts which are most subject to wear become worn in the course of time this wear is continually and automatically taken up.

A further objectof the invention is to provide a compressor which would be highly efiicient in operation, delivering a maximum quantity of compressed gas' per unit of power.

' With the foregoing and other objects in view which will be made manifest as the description proceeds, and specifically pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein:

Fig. 1 is a view in section illustrating the end of the improved compressor in elevation and may be considered as havingbeen taken upon the line i--l upon Fig. 2.

Fig. 21s a firtical section through the improved compressor taken upon the section line 2-4 upon Fig. 1. r

Fig. 3 is a transverse vertical section taken upon the broken section line 33 upon Fig. 2.

Fig. 4 is a longitudinal section taken upon the line 4-4 upon Fig. 3.

Fig. 5 is a vertical transverse section taken upon I the line 5--5 upon Fig. 4.

Fig. 6 is a view in elevation, parts being shown in section, illustrating one of the parts making up a cylinder'head for one of the cylinders of the improved compressor. i

Fig. 7 is a sectional view taken substantially upon the line ll-i upon Fig. 6.

Fig. 8 is a sectional view illustrating details of construction of the oil pump used as a means for lubricating the parts of the improved compressor.

Fig. 9 is a sectional view through one of the pistons which are preferably employed in the construction of the improved compressor.

Fig. 10 is a view partially in elevation and partially in section illustrating the drive shaft and the details of construction of the gyratory oscillator and the means for connecting these parts together.

Referring to the accompanying drawings, wherein similar reference characters designate similar parts throughout, the improved compressor consists of a hollow, cylindrical body It! having an end wall H in which is formed a central bore l2. The opposite end of the body is closed by means of a removable cover or closure l3 held in place by means of screws l 4 closing chamber l5.

A drive shaft I6 extends into bore l2 and has a shoulder ll thereon (see Fig. 10) against which is pressed the inner race of a ball bearing or other anti-friction bearing, indicated at I 8. Against anti-friction bearing l8 there is pressed onto shaft IS a cam or eccentric l9 and a second ball hearing or anti-friction bearing 26 is pressed onto the drive shaft against the cam.

The inner end of the drive shaft is reduced and threaded to receive the disk 2| which may be locked in place thereon by means of a nut 22. The drive shaft with its associated bearings is inserted into bore l2 and positioned against a shoulder 23 therein, after which disk 2| and nut 22 are applied to the drive shaft in chamber 15.

A packing means 24, which may be of any preferred, construction, such as a sylphon, is applied to drive shaft l6 and has its inner end arched by a spring 25 into engagement with shoulder ll. This construction is designed to prevent leakage of any gas from the interior of the compressor up the drive shaft. The spring is compressed between a flange about the sylphon and a cover plate 26 which covers the end of bore l2 and which is fastened in place against a gasket 21 by means of screws 28. The drive shaft is rotated and preferably carries a fly 'wheel 29 which is provided with blades or vanes 30 so arranged that l on rotation of the fly wheel the blades will blow an air blast horizontally across the body of the compressor. The fly wheel may be rotated by means of a. belt 3| driven by means of an electric motor not shown.

The function of the cam or eccentric I9 is to operate an oil pump. The body I0 has a vertical bore 32 in which is reciprocable a piston 33 having its upper end urged into engagement with the cam or eccentric I9 by means of a spring 34 disposed within the bore. The lower end of the piston is provided with a pin 35 extending into the upper end of the spring and forming a shoulder constituting a spring seat. The lower end of bore 32 is connected by means of a fitting 36 and a.

tube 31 to an oil reservoir or source of lubricating oil. The fitting 36 provides a valve seat for an intake valve 38, which is urged into seating position by means of a .coiled spring 39. This valve, constituting the intake valve to the oil pump, is housed within a valve cage 4fl which is held down against the fitting 36 by the lower end of the coil spring 34. The cage, as clearly shown in Fig. 8, provides a spring seat for the spring.

A horizontal bore 4| establishes communication between bore 32 and a fitting 42 disposed within chamber l5 and which has connected thereto a tube or pipe 43. In bore 4| there is a.,valve seat 44 for a spring closed exhaust valve 45. The spring 46, which urges the valve 45 into closed position, is compressed between the ball valve and the fit-- ting 42. d

The operation of the pump is as follows: Dur

ing rotation of the drive shaft 16 the cam or eccentric l9 produces reciprocation of piston or plunger 33. On the downward stroke of the piston or plunger, the intake valve 36 closes and the oil is forced out of bore 32, past exhaust valve 35, and into tube or pipe 43. On the up stroke of the piston or plunger 33, which is accomplished by spring 34 keeping the plunger in contact with the rotating cam, the exhaust valve 45' closes and oil enters bore 32 past the intake valve 38. Ball check valves are suitable for use in conjunction with the oil pump. In as much as these valves are operating in a liquid they will not become noisy nor create any obectionable noises in the compressor.

The end of the body In is bored out at regular intervals about the drive shaft andaround bore l2 to receive spaced sections of seamless tubing 50, 5|, 52, and 53. These sections of seamless tubing form a circular row of cylinders disposed about the axis of rotation of the drive shaft. They are pressed into the bores in the end of the body l0 so as to be firmly mounted therein. Pistons 54, 55, 5B, and 51 are reciprocable in the cylinders, respectively. a

/As a means for imparting reciprocatory movement to the pistonS each piston is made slightly longer than its respective cylinder and has its inner end provided with a flange 58 constituting a spring seat for a spring 59. Each spring 59 is compressed between flange 58 and the end of the body serving to urge each piston from right to left as viewed in Fig. 4 or to urge each piston in the direction of its intake stroke.

As a means for moving the pistons on their compression strokes against the action of the springs 59, a gyratory oscillator is mounted within chamber IS. The cover or closure l3 carries a ball 60 on which is seated one end of the oscillator so as to be mounted for universal movement thereon. The ball is disposed in alignment with the axis of rotation of the drive shaft and the opposite end of the oscillator is connected to the drive shaft so as to be swung through a circle thereby. The gyratory oscillator consists of a flanged body 6| having a removable axial seat 62 for the ball 60. It also has a tubular extension 63 within which is receivable a sleeve 64-. Inside of .the sleeve 64 there is disposed a spindle 65 which is rotatable in sleeve 64 and which is mounted therein by means of anti-friction bearings 66 and 61. The inner race of bearing 61 is held in place on spindle 65 by a screw 68, and a spacer or washer 69 is tightened against the inner race of bearing 66 by means of a nut 10.

A leaf spring, which is angular in form and which is indicated at H, is recessed in the face of disk 2| and held in place thereon by means of nut 22. 12 merely designates a counterweight threaded into disk 2| through spring LI serving to assist in holding the spring in place and to counterbalance the eflect of the connected end of the gyratory oscillator. The sleeve 54, spindle 65, and associated structure, are detachably connected to the body of the oscillator by means of a screw 13.

During rotation of the drive shaft l6 spring II acts as a crank swinging 'the end of the spindle 65 through a circle, the center of which is coincident with the axis of rotation of the drive s haft. The gyratory oscillator is thus caused to go through a conical revolution about the center of ball 60 as the center. The flange 6| of the gyratory oscillator has pivotally mounted thereon a fork 14 which embraces the fiat sides 15 on a guide 16 which is mountedfor rotation on a pin aioeaae or arbor Ti mounted on closure or cover it and extending into chamber is.

By this construction it will be noted that although the end of the gyratory oscillator, which is connected to spring H, is swung through a circleabout the axis of rotation of drive shaft it, the gyratory oscillator, itself, is not axially rotated. The fork it merely slides back and forth on guides it holding the oscillator against axial rotation although permitting the flange ti to oscillate as is required by the motion imparted to the oscillator by the rotating spring H.

The flange M is provided with recesses opposite the ends of the cylinders and these recesses receive the balled ends it on transmitters E9. The opposite ends of the transmitters F9 are also balled, as indicated at 811, and of the recesses on removable seats 8!, which are mounted within the hollow pistons. As the drive shaft l6 rotates, the end of the gyratory oscillator is swung about the center of ball 60 as the center, causing the flange 6i to tilt progressively and the motion of the tilting flange is such as to cause the transmitters T9 to consecutively move the pistons from left to right, as viewed in Fig. 4, or in the direction of their compression strokes. The flange will first cause the transmitter it to move from left to right, as viewed in Fig. 4, compressing the gas in the cylinder and compressing spring 59. As the gyratory oscillator; continues its movement the flange iii moves so as to allow the piston to be moved by spring 59 in the direction of its intake stroke.

By .this form of construction it will be appreciated that the conventional connecting rod with its bearings is eliminated. The piston is positively forced by its mechanical construction on its compression stroke and is returned on its intake stroke by the spring 59. The spring not only keeps the piston in engagement with the transmitter but also takes up all wear which may take place between the transmitters l9 and flange 6i and between the balledends so and their seats 3! so that at all times loose play between the parts which might otherwise result from Wear, is taken up. The motion is such as to cause the pistons to be consecutively moved on theircompression strokes and, consequently, the springs 59 on the turn of the flange 6i will consecutively return the pistons on their intake strokes. 1 I

The pistons are so designed that at the extreme end of their compression stroke the head of the piston approaches very closely the end of the cylinder. Should any wear take place, the springs 59, in taking up the wear, merely move the pistons toward flange M, which results in an increased clearance between the head of the piston and the cylinder head, the increase in clearance being equal to the actual wear and being very small.

Each bore in the end of the body iii which receives the cylinders is enlarged to form an annular groove 82 surrounding each cylinder. Each cylinder is provided with a circular row of apertures or perforations 83 which communicates with the groove.

Referring now to Fig. 5, tube or pipe 84! constitutes an inlet or gas supply. This is connected to a fltting 85 mounted on top of body it and which may be provided with an adjusting valve 86. Connected to the fitting there may be a tube or pipe 8'? leading to a pressure gauge, and a tube or pipe 88 may lead to a switch which starts and stops the electric motor which drives the compressor. Fitting 85 communicates with a vertical bore 8d in the top of body it and two downwardly divergent bores 9d and M communn cate with bore 89 above its bottom. These divergent bores communicate with the grooves 82 surrounding the cylinders sothat gas to be compressed may flow through pipe 351 through fitting 85 into vertical bore 89 and therefrom through divergent bores 9i and Qi into grooves 82 and be permitted to pass through perforations 83. l

Each piston is hollow and is provided with several annular rows of perforations. Each piston is shown as being provided with three annular rows of perforations indicated at 92, 93, and 9%. These are arranged to pass perforations 83 on reciprocation of the piston. The pistons are preferably relieved by grooves adjacent perforations in the piston is to establish communication between the interior of the piston and perforations 83 at several different points along the intake stroke of the piston. I

Each piston may be provided with one or more piston rings and the extreme end of the piston is reduced, as indicated at 96. A series of perforations Q? is formed in the end of each piston, establishing communication between the interior of the piston and an annular groove 98, at the sides of which there are seating surfaces for the ring valve 99 which is preferably provided with a piston ring we. The ring valve 99 does not closely fit on the reduced portion at but there is a small clearance which is clearly indicated at ml. A perforated cap W2 is fastened onto the end of the piston by means of screws I03 and has perforations IN. This can is positioned as to permit a slight reciprocation of the ring valve v99 between the face of the cap m2 and the seating surfaces at the sides of groove 98.

During the compression stroke of each piston the ring valve is in the position, with respect to the piston, as shown in Fig. 9 wherein it is seating against the seating surface at the sides of groove 98 and closing perforations 9'8. The friction of the ring Wt on the ring valve bearing on the interior of the cylinder, together with the pressure developed by the piston on the gas in the cylinder, when the piston is undergoing a compression stroke, firmly maintains the ring valve 99 seated, closing the piston and enabling the piston to compress the gas in the cylinder.

Whenthe piston reaches the end of its compression stroke and starts on its intake stroke, the friction of the piston ring 886 with the interior of the cylinder holds the ring valve 9? stationary during the initial movement of the piston so that the initial movementof the piston is relative to the ring valve 99, causing perforations at to open. Asthe rows of perforations 92, 93, and Q 3 consecutively pass perforations 83, gas is admitted to the interior of the piston and is permitted to flow through perforations 97. The ring valve 9Q being open or against the face of cap we the gas flows through perforations W and IIlIl again holds the ring valve stationary during the initial movement of the piston on its compression stroke so that the initial movement on the compression stroke of the piston is relative to the stationary valve, causing the valve to immediately seat on the seating surfaces at the sides of groove 98. In this way the valve is mechanically closed at the very start of the compression stroke and the closing of the valve does not depend upon the pressure developed in the cylinder by the piston while undergoing a compression stroke.

The length of movement of ring valve 99 with respect to the piston is very small and because of the fact that the ring valve is light in weight and is not moved back and forth with any considerable force by the piston at the end of the stroke, this type of intake valve construction in the compressor is not only positive in its action but is very quiet. In this way the gas that is to be compressed is admitted to the cylindersfrom the divergent bores 90 and 9I, passes into the pistons through the ends of the pistons, and is entrapped in the cylinders beyond the ends of the pistons. At the very start of the compression stroke, ring valve 99 closes so that the compres: sion action of the piston is effective throughout the entire length of stroke of the piston.

The ends of the cylinders are closed by means of cylinder heads. Each cylinder head is made up of two parts I05 and IE6 which'are bolted together and to the end of the body by means of bolts or cap screws IIB'I. Suitable gaskets Int may be interposed between the parts and between part I95 and the end of the body. The innermost part I05 has an aperture I09 formed therein. This aperture is so arranged as to be located at the very bottom of the cylinder (see Fig. 3). The purpose of having the outlet aperture I09 located at the very bottom of the cylinder is to enable ready escape of any oil which may enter the cylinder and which will be disposed therein in liquid form. If the outlet aperture were located above the bottom it would be necessary for the oil to build up into a column between the end of the piston and the cylinder head part I05 before the oil could flow .out of the outlet aperture.

With the present arrangement the movement of the piston in the direction of its compression stroke merely washes the oil out of the outlet aperture. The outlet aperture is closed by.an exhaust valve. The outer face of part I05 is re.- lievd or recessed as indicated at Hit and in the recess there are formed a projecting shoulder I I i and a-projecting valve seat I I 2 surrounding outlet passage I09. The reed type valve is employed. this being in the form of a thin section of sheet steel or the equivalent, indicated at H3, having an angular extension II which is recessed in cylinder head part I05.

A cage H5 is fastened to part I05 by screws H8 and this encloses a reversely bent leaf spring III which is fastened to the cage by a bolt, I Iii. Near the reverse bend the spring bears against the reed, holding the reed against shoulder III.

.The spring carries a macarda button I I9 which 'and which .are formed in the walls of the cage are sufficient to permit exhaustion of the gas and oil therethrough. The reed type valve employed is highly efficient in that it is quite silent in its action, and being of a floating type reed in as much as the extension II4 loosely fits in its re.- cess in part I05, the valve will always seat without leakage. The edge of extension I4 rests against the back or bottom of the recess so that when the reed opens it rocks or turns about this edge as a fulcrum or center. This rocking action of the reed about the edge of the extension II4 as a center is such as to enable the silent action of the valve. Spring II'I keeps the extension pressed against the bottom or back of the recess in addition to urging the reed into closed position. The outer part I96 of the cylinderhead is concave, as indicated at I2I, to receive the cage and its valve and to provide an exhaust chamber into which the expelled gas is delivered. Fittings I22 are connected to each of the outer parts I06 of the cylinder heads, and tubes I23 connect the fittings with a common manifold not shown. This leads to a condenser, not shown, from which the gases in the mechanical refrigerating system are conveyed to the cooling coil of the refrigerator. When the gases have expanded or volatilized in the cooling coil they are returned to the compressor through inlet pipe or tube 84.

On entering the vertical bore 89, the oil, which is carried in the form of fine globules by the gas which is volatilized in the cooling coil, is deposited in the bottom of the bore and is returned to chamber I5 through a bore I26 (see Fig. 2). The gases whiclfpass downwardly through the divergent bores 90 and M are returned to the cylinders to be recompressed. In this way there is a continual separation of oil from the gas in the refrigerating system and a return of the oil to the. chamber I5 so that chamber I5 is never emptied of its oil content and all parts of the apparatus therein are thoroughly lubricated. The primary means-of lubrication in chamber I5 is accomplished by the oil pump which is driven by means of cam. or eccentric I9. This oil pump receives oil through tube 3! from a suitable source of supply, such as an oil reservoir. It pumpsthe oil into pipe 43. This pipe is connected at its upper end to a T-fitting I26 which is mounted on a bracket I 21 inside of chamber I5. The T-fitting has connected to its ends the U-shaped tube or pipe' I28 which is perforated on its under side. This U-shaped tube or pipe is arranged in the top of.chamber I5 so that its perforations discharge downwardly over the cylinders and the projecting portions of the pistons. At the center of the tube or pipe I28, which is directly opposite the T-fitting, there is formed a large perforation. I28a which is arranged to discharge into a cup I29 which is on a small nipple or tube I30. This tube or nipple is screwed into the boss I M on which ball is formed, and a passage I32 is formed therein delivering the oil which is caught in cup I 29- to the ball. The passage I32 terminates on the end of the balland the oil discharges therefrom against the surface of the removable seat 62.

In the seat there is formed an aperture I33 through which the oil which is discharged through the ball may pass so as to lubricate bearing 5?. The interior of sleeve 64 may fill with oil and egress for oil is permissible through the other bearing 66. The rotating or swinging end of the gyratory oscillator tends to throwoutcoming oil which passes through bearing 65 and assists in distributing it through chamber I5.

Bracket I217 provides a small trough I34 and there is an aperture, I35 formed in tube or pipe d3 immediately before it connects to the T-fltting H26. Some of the oil which is pumped by the pump is discharged through this aperture and is collected by trough ltd.

A horizontal bore lit is formed in the end of the body, which communicates with the vertical bore l3'i therein. This, in turn, communicates with bore l2 so that the bore receives an adequate supply of oil in which the drive shaft rotates. As clearly shown in Fig. 10, the cam or eccentric H) has a pair of radial bores I38 formed therein which communicate with a longitudinal bore ltd. The ends of the longitudinal bore are arranged between the races of the bearings 20 and i8.

When the oil is discharged into bore 52 from passage it'll the rotating cam in bore l2 not only serves to reciprocate plunger 33 but acts somewhat as an oil pump in that on each revolution the high point of the cam in which bores 938 are located, on swinging near the bottom of bore it, causes the oil to be forcedup into these bores and be'distributed to bearings l8 and 29 through longitudinal bore or duct 39. The oil in bore 02 is confined therein at one end by cover plate 2b and sylphon 26. It may drain through bearing 26 back-into chamber 85. The oil that is distributed 'in the chamber is ultimately collected in the bottom of the chamber in which there is screwed. a fitting Mu to which a tube or pipe Hill is connected which leads to a suitable oil reservoir, not shown.

The inlet tube or pipe 3?, which supplies the oil pump with oil, receives its oil from the oil reservoir so that in operation the oil is pumped, distributed to the various working parts so as to thoroughly and completely lubricate them, and

returned to the reservoir. In the natural course of operation the gas on being compressed will pick upsome of the oil and carry it through the system but there is a continuous separation of oil from gas in vertical bore 89, which returns the picked-up oil back to the chamber and into the oiling system.

In assembling the construction, the drive shaft Mi, with its bearings it and 2t and its cam it, may be inserted into the body from the ring hand end, as viewed in Fig. 2. The sylphon may be applied and the cover plate 26 secured in place. The disk 21! carrying counterweight l2 and leaf spring ii is then fastened to the end of spindles 65, with which is associated the bearings 6's and 66 and sleeve 5d. The body of the gyratory oscillator is left removed from sleeve M. The disk 20 with its attached spindle is then applied to the end of the drive shaft.

The purpose of using leaf spring H as a means for swinging the end of spindle 65 will now be I explained. If the angular arm of the spring H were rigid some difiiculty would be encountered in inserting the body of the gyratory oscillator in the open end of chamber i5 and at the same time causing sleeve 6% to'enter the tubular extension 63. By having the part ii in' tory oscillator has been inserted, the part TH does not function as a spring but merely as an arm or crank for swinging the end of the spindle.

I a compressor.

The sole purpose of making the part it a leaf spring is so that the parts may accommodate themselves to the necessary relative positions in assembling and connecting sleeve 66 with tubular extension 63.

When the parts have been assembled they are locked together by means of set screw 13 which is tightened by inserting a screw driver and thereafter a socket wrench for tightening the lock nut through an aperture M32 in the top of the body. This aperture is normally closed by a threaded plug M3.

On tightening the vcover H3 in place, which is done prior to tightening set screw it, the body of the gyratory oscillator is forced inwardly by ball t8 into engagement with the balled ends it of the transmitters. The springs which are efiective on the pistons always maintain the transmitters in firm engagement with the flange of the gyratory oscillator.

Conversely, whenever it is desired to disassemble the construction for purposes of inspec-= tion, repair, or replacement of parts, this can be very easily accomplished by removing plug M3, loosening set screw it, and then removing cover is. The removal of the cover enables all parts within chamber it to be removed, replaced and/or repaired.

From the above described construction it will be appreciated that a novel and advantageous refrigerating system is provided which employs In the system the gas, which is caused to pass through a closed circuit in which the'compressor is installed, is allowed to pick up any oil which is naturally inherent in a system of this character. However, instead of being allowed to continually remove the oil from the chamber it of the compressor and deposit the oil elsewhere in the circuit with the ultimate result crank shafts, the bearings for such parts, wrist I pins and their bearings, and eccentrics and eccentric straps. Such parts tend to produce vibration and are subject to extreme wear. In the present construction the arrangement is such as to take up wear at all times so that bearing surfaces will always be kept tight and noise from this source is entirely eliminated. In the event that part of the compressor does wear, the only effect is to increase the clearance between the ends of the pistons and their cylinder heads at the end of the compression strokes. This increase in the clearance will be so small as not to be objectionable.

The valve arrangement on the piston is such as to be substantially noiseless and is advantageous in that the arrangement of the valves at the ends of the piston does not allow of a large volumetric space in the end of the piston in which compressed gas will merely compress and expand on each stroke of the piston. On the contrary, a very high percentage of the gas admitted to each cylinder on each stroke is compressed and completely expelled from the cylinder. The exhaust valves are of such design as to be substantially noiseless and leak proof. In as much as the cylinder heads and the exhaust valves, which are subjected to the greatest increase in temperature when the compressor is in operation, are located immediately before blades 3@ on the flywheel.

these parts are subjected to the greatest cooling action of the air blast created by the fly wheel.

From an inspection of Fig. 4, which illustrates two pistons at opposite extremes of their strokes, it will be readily apparent that the transmitters l9 deviate only slightly from the centers of their cylinders. In other words; the transmitters during reciprocation of the pistons are at all times virtually in direct alignment with the direction of movement of the pistons. In this way wear on the sides of the pistons and on the sides of the cylinders is reduced and friction between these parts is a minimum.

While the number of cylinders employed has been illustrated as being merely four, it is obvious that the number of cylinders may vary under different circumstances.

A very incidental feature of the improved compressor is as follows:

In the event that any moisture should enter the circuit traveled by the gas and should combine with the gas, which may be sulphur dioxide, forming sulphurous acid, which would attack the various metal parts, the sulphurous acid, in so attacking the parts, may tend to cause a piston to freeze in its cylinder. If the piston which has become frozen is frozen at the end of its compression stroke, this does not in and of itself result in locking of the compressor so that the electric motor used for driving it will burn out. The motor may continue to operate "under such circumstances when its circuit is closed and the gyratory oscillator is caused to conically revolve. The transmitter of the piston which may have been frozen at the end of its stroke merely moves away-from its seat M in the piston and is reciprocated back and forth in the hollow piston.

Retainers I44 are mounted on the flange of the oscillator and extend over the balled ends it of the transmitters so that the transmitters will remain connected to the oscillator and will be pulled away from seat 8|! instead of merely falling to the bottom of the frozen piston to be engaged by the oscillator during its conical revolution. In this way it is apparent that under certain conditions even though moisture should enter the gas system, which ordinarily would be disastrous, that some protection is afforded the electric motor even when a piston has become frozen, provided it freezes in the cylinder at the end of the compression stroke.

Various changes may be made in the details of construction without departing from the spirit or scope of the invention as defined by the appended claims.

I claim:

1. A compressor comprising a hollow body, a drive shaft rotatably mounted in the end of the, body, means providing a plurality of cylinders in the body arranged about the drive shaft, pistons reciprocable in the cylinders, a flanged gyratory oscillator mounted for conical revolution about a point co-axial with the axis of rotation of the drive shaft, means connecting the oscillator to the drive shaft to be revolved thereby, and transmitters operatively connecting the flange of the oscillator to the pistons so as to cause the pistons to be moved thereby in the direction of their com pression strokes, said pistons being flanged, and springs surrounding the cylinders engaging the flanges on the pistons and urging the pistons in the direction of their intake strokes and against said transmitters.

2. A compressor comprising a hollow body, a drive shaft rotatably mounted in the end of the amazes body, means providing a plurality of cylinders in the body arranged about the drive shaft, pistons reciprocable in the cylinders, a flanged gyratory oscillator mounted for conical revolution about a point co-axial with the axis of rotation of the drive shaft, means connecting the oscillator to the drive shaft to be revolved thereby, and

transmitters operatively connecting the flange of the oscillator to the pistons so as to cause the pistons to be moved thereby in the direction of their compression strokes, said pistons being flanged, and springs surrounding the cylinders engaging the flanges on the pistons and urging the pistons in the direction of their intake strokes and against said transmitters, an oil pump driven by the drive shaft, and means for discharging the oil pumped by the pump in the interior of the body.

3., A compressor comprising a hollow body, a drive shaft rotatably mounted in the end of the body, means providing a plurality of cylinders in the body arranged about the drive shaft, pistons reciprocable in the cylinders, a flanged gyratory oscillator mounted for conical revolution about a point co-axial with the axis of rotation of the drive shaft, means connecting the oscillator to the drive shaft to be revolved thereby, and trans-' mitters operatively connecting the flange of the oscillator to the pistons so as to cause the pistons to be moved thereby in the direction of their compression strokes, said pistons being flanged, and springs surrounding the cylinders engaging the flanges on the pistons and urging the pistons in the direction of their intake strokes and against said transmitters, an oil pump driven by inent about a fixed point at one end which is disposed centrally of the row of cylinders, guide means for holding the oscillator against axial rotation, means arranged centrally of the row of cylinders and extending therebetween for swinging the other end of the oscillator through a circle, and means operatively connecting the oscillator to the pistons.

5. In a compressor, a drive shaft, means providing a plurality of cylinders arranged about the drive shaft, means providing a ball opposite the end of the drive shaft, a gyratory oscillator mounted for conical revolution about the ball, means operatively connecting the oscillator to the drive shaft, pistons reciprocable in the cylinders, means operatively connecting the pistons to the oscillator so as to be reciprocated thereby upon conical revolution of the oscillator, and an oil pump driven by the shaft for lubricating parts of the compressor.

6. In a compressor, a drive shaft, means providing a plurality of cylinders arranged about the drive shaft, means providing a ball opposite the end of the drive shaft, a gyratory oscillator mounted for conical revolution about the ball, means operatively connecting the oscillator to the drive shaft, pistons reciprocable in the cylinders, means operatively connecti'ng the pistons to the oscillator so as to be reciprocated thereby upon conical revolution of the oscillator, an oil p mp driven by the shaft for lubricating parts of araee 27 the compressor, and meansior conveying oil from the oil pump to the ball.

7. In a compressor, a drive shaft, means providing a plurality of cylinders arranged about the drive shaft, means providing a fixed bearing opposite the end of the drive shaft, a gyratory oscillator mounted for conical revolution about the fixed bearing as a center, means operatively connecting the oscillator to the drive shaft, pistons reciprocable in the cylinders, and means operativeiy connecting the pistons to the oscillator so as to be reciprocated thereby upon conical revolution by the oscillator.

8. In a compressor, a drive shaft, means providing a. plurality of cylinders arranged about the drive shaft, means providing a fixed bearing opposite the end of the drive shaft, a gyratory oscillator mounted for conical revolution about the fixed bearing as acenter, means operatively connecting the oscillator to the drive shaft, pietons reciprocable in the cylinders, means operatively connecting the pistons to the oscillator so as to be reciprocated thereby upon conical revolution by the oscillator, and means for holding the oscillator against rotation during its movement.

9. In a compressor, in combination, an exhaust port, a reed for opening and closing said exhaust port, said reed having an angular extension on the edge of which the reed rests, and spring means holding the reed so as to be supported by the edge of its extension and urging the reed into closed position. r

10. In. a compressor, in combination, an exhaust port, a reed for opening and closing the exhaust port, said reed having an angular extension disposed in a recess adjacent the exhaust port, a reversely bent spring engageable with the reed to press its extension against the bottom of the recess, and a button carried by the spring engageable with the reed urging the reed into closed position. v

11. In a compressor, in combination a cylinder, an outlet valve controlling the outlet from the cylinder, said outlet valve comprising an angular reed loosely mounted and resting on its 1 angled end for engagement with a seat and a leaf spring urging the reed against the said seat. BYRON RAY BURKE. 

